condition mean min max ZT0-3 19.8835 19.8835 19.8835 ZT4-7 19.3352 19.3352 19.3352 ZT8-11 16.3944 16.3944 16.3944 ZT12-15 17.1477 17.1477 17.1477 ZT16-19 18.973950000000002 18.973950000000002 18.973950000000002 ZT20-23 19.0752 19.0752 19.0752